O99.1Header code — not billable

Other diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism complicating pregnancy, childbirth and the puerperium

Short description: Other dis blood/immune compl preg/childbrth

Chapter
15. Pregnancy, childbirth and the puerperium
Category
O99
Effective date
October 1, 2026

Related codes in category O99

O99Oth maternal diseases classd elsw but compl preg/chldbrthO99.0Anemia complicating pregnancy, childbirth and the puerperiumO99.01Anemia complicating pregnancyO99.011Anemia complicating pregnancy, first trimesterYesO99.012Anemia complicating pregnancy, second trimesterYesO99.013Anemia complicating pregnancy, third trimesterYesO99.019Anemia complicating pregnancy, unspecified trimesterYesO99.02Anemia complicating childbirthYesO99.03Anemia complicating the puerperiumYesO99.11Oth diseases of the bld/bld-form org/immun mechnsm comp pregO99.111Oth dis of bld/bld-form org/immun mechnsm comp preg, 1st triYesO99.112Oth dis of bld/bld-form org/immun mechnsm comp preg, 2nd triYes

Frequently asked questions

What is ICD-10 code O99.1?

O99.1 is an ICD-10-CM diagnosis code for Other diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism complicating pregnancy, childbirth and the puerperium.

Is O99.1 a billable code?

No. O99.1 is a category/header code, not billable on its own — use one of its more specific child codes instead.

What ICD-10-CM chapter is O99.1 in?

O99.1 falls under Chapter 15: Pregnancy, childbirth and the puerperium.

When did O99.1 become effective?

O99.1 has been effective since October 1, 2026, per the CMS/CDC ICD-10-CM annual release.

What other codes are related to O99.1?

O99.1 belongs to category O99, which includes 12 other codes — see the related codes list on this page.

ICD-10-CM data maintained by CDC/CMS (public domain). Always verify codes with authoritative sources before making coding or billing decisions.